Thought I would just rant here, had a small profit this morning and now completely in the negatives.
Stats of my Campaign earlier
Targeting 30 million people
0.5 CTR = 0.07 CPC
Later in the Day, same amount of people targeted but increased my budget from 100 to 500
0.7 - 0.8 CTR! = 0.50 CPC (What the F*cking f*ck is going on??)
Dunno what country you're running in, but from what I heard and what I see in Germany, a lot of big brands are coming up for the summer / holidays with their new offers and are basically inflating the bids. Pretty similiar to before the year ends, budgets are left, christmas coming, otherwise somebody more into facebook might give a better explanation.
#1 never increase your budget at the mid of the day.
#2 always cap your bids before increasing budget.
Raising your budget, especially by such a large amount, is what killed you. Also it's pretty common for CPC's to increase as the day goes on. At least if you're running in EU countries. My accounts are all in PST.. at the start of the day CPC's will be extremely low, but as the day goes on CPC's tend to increase pretty significantly. This is possibly due to the fact that later in the day (PST time) people in Europe are going to sleep, and thus CTR's are lower. Lower CTR = higher CPC.
Facebook is completely random. Something I've learned about FB is that you literally cannot properly split test anything, because everything is COMPLETELY random. My last statement is 100% serious and not a joke, btw
Ok that makes sense. I am running USA campaigns. Should I just open it a high budget in the middle of the night and leave it? Thanks
Facebook is trying to make more money...? lol.
They're killing us affiliate marketers, it's driving me nuts. It's not even a very viable source unless you're cloaking.
You have to pay attention to FREQ, maybe your 0.5 ctr FREQ is higher than your 0.7 ctr ad, thats why 0.5 ctr paying lower
He means drop your bids to set your own ceiling first. Example, you are bidding $0.47. You are getting $0.17 clicks on average. Before upping your budget, you should drop your bids to say $0.20 so that, with the increased volume, you have put a lid on the CPC FB is able to charge you.
seem back to normal now for me at least anyway
I'm seeing cheap CPCs again. CPCs are 0.02-0.05 cents for a 5 million demo in the US 
-Aaron
Anyone seeing low volume today? Mine has ground to a halt.